Like I said, Takara did this with Microman. The whole point is that they were trying to appeal to older kids by showing off the customizability of the figures. This was around the time the plastic model industry started taking off. Magazines like Hobby Japan created a sort of fad of customizing various model kits from cars to Mobile Suits. So, Takara naturally wanted to cash in on the fad by showing that you could do the same with action figures. This is also the reason why Takara included model kits in the microman line and why there were Transformers models in the 80s as well.